Technical Q&A with Lennard Zinn: Safe crank removal?

By Lennard Zinn

Published Oct. 5, 2010

Updated Oct. 5, 2010 at 10:02 AM EDT

Dear Readers and Campagnolophiles,
I had promised to follow up on Power Torque crankset removal when I found out the solution. Arguably, the solution does not yet exist for American consumers, but I can tell you what I now know about it, namely that removing Campagnolo’s new Power Torque crankset is still an issue.

Here is Campy’s video on installation and removal. However, from what I have found out, that puller tool shown in the video is made by Cyclus in Erfurt, Germany and is not currently available in the USA. In fact, it does not appear on the Cyclus website yet. Furthermore, Campagnolo recommends against using that tool on a carbon crankarm, since it could mar the carbon, so I am not at all sure how one would remove a carbon Power Torque arm currently without damaging it.Lennard

Dear Lennard,
Recently a shop mechanic told me that they had received a tech bulletin from Giant that told them not to use petroleum based chain lubes on bikes with carbon fiber frames. The reason, he said, was if there is any “micro-cracking” (his words) that the lube could seep into these cracks and damage the frame.

Are there any merits to this claim? I currently use Pro-Link Gold. Should I switch to a wax based lube? If so what do you recommend?Derek

Dear Derek,
It is not a concern. We’ve been over this type of thing in this column regarding grease on carbon seatposts, and it’s not much different here. You’re not going to damage anything.

This is what a Giant representative told me in response to your question: “Giant never sent out any sort of technical bulletin regarding this matter. We’ve never heard of any sort of lubricant exacerbating frame degradation. If an owner has a bona-fide crack, then we suggest the owner returning the frame to a certified dealer for inspection.”

In addition, here are some other responses from other companies on the subject:

From Specialized
The resin we use is a thermoset Epoxy, which isn’t soluble by petroleum-based products. If you were using a thermoplastic, you’d have to worry more about water/chemical absorption, but thermoplastics are unaffected due to their tightly cross linked molecular structure.

If you have an environmental problem, it’s always a matrix (resin) that is damaged environmental problems (UV, chemical, heat etc.), not the carbon fiber.

Any of our carbon frames/components are painted and clear coated with materials that are not degraded by petroleum based lubricants.

Bigger concerns for un-coated carbon composite parts are UV degradation and water absorption – both of which are mitigated with our paint and clear coat process.Mark Schroeder
Director, Specialized Test Lab

From Warp9 Bicycles
I think he must have heard wrong, or maybe Giant is using a material different than the rest of us. The composite material we use is a carbon-epoxy composite.

Other types include Polyester Resin, Vinyl Ester Resin, among others. Epoxy is the most expensive, but also the strongest, and temperature stable (no warping at hot temps). The epoxy matrix is very durable and resists most common chemicals. Here is a chart of chemical compatibility for common epoxy.
Notice that kerosene, diesel, gasoline, jet fuel, hydraulic fluid, and other petroleum products are quite safe on the general epoxy material.

I just wrote to my friend Judd Frost who ran our prototypes division in San Diego for Alpha Q until it folded [ed. note; Hull was formerly also with AlphaQ]. He now works in R&D at Goodrich Aerostructures in San Diego. He confirmed this and also added “All epoxies are not created equal but most are resistant to chemical attack. We soak (for multiple days) our unpainted test specimens in jet fuel, MEK, acetone… and other nasty stuff before test and we don’t expect a drop in mechanical properties. To be sure, it would be best to find out what epoxy is being used for that component and check with the epoxy supplier. Epoxies are made with different tougheners that could come under chemical attack. I don’t see an issue at all but now that more and more stuff is made in China, I think corners are cut on expensive ingredients and there is a wider base of epoxies that could be an issue. The fiber itself? No issue. The epoxy is the only concern.”

Most of us smaller companies and medium sized ones are buying our pre-preg material from a handful of suppliers like Hexcel, Toray, Newport, and that material is typically pre-preg (previously impregnated with epoxy resin) rather than dry cloth that is wetted on site. I have read on Giant’s webpage that they are the only bike manufacturer to weave their own cloth, so it is possible that they have switched to a different epoxy system that what is commonly available from the common suppliers. You would have to ask them if they are doing something new that is no longer petroleum resistant. As for the rest of us, our parts are resistant to petroleum cleaners and lubes.

From Giant’s web page “State-of-the-art T-800 raw composite material is painstakingly woven in Giant’s own composite factory (a step no other major manufacturer undertakes), then hand-crafted into framesets using Giant’s most advanced construction technique. Fusion. The process produces the lightest, stiffest and most ride-compliant framesets ever to roll on two wheels.”Bert Hull
President, Warp9 Bicycles

Dear Lennard,
I have a quick question for you regarding my Mavic Ksyrium SL rear wheel. Behind the freehub, next to the drive side hub flange on the rear wheel is a rubber seal. I am assuming this is there to prevent dirt, water, grit, etc from entering the interior of the freehub body and messing with the ratchet mechanism, pawls, interior bearings, etc.

My question is: should this seal be lubed or greased in any way, or should it remain dry so as to not attract any unnecessary dirt? My thought with greasing it is that it might help seal out water a bit better, as I found some water contamination inside the freehub body after several days of wet, rainy riding on a recent multi-day bike trip. Also, I used Pedro’s Syn-Lube to re-lube the pawls and inner ratchet teeth of the freehub body. Is this satisfactory? I read recently that Phil Wood Tenacious Oil was approved by Mavic, but that seemed a bit heavy to me.

Thanks for all your help, your great books, and your informative column.Bill

From Mavic’s tech specialist Bill Douglas:
We don’t lube the seal but I’m sure some oil gets on it during reassembly. Synlube is far too light in viscosity, and no longer in production. Phil’s Tenacious is heavier than our lube but preferable if ours isn’t at hand. It’s not endorsed by us officially but is fine to use in a pinch.Bill Douglas

While this may be true depending on the condition of the frame, I wanted to remind you that Cannondale supports its frames with a lifetime warranty.

Even in the event that they will not cover the frame completely, they also have an outstanding crash replacement program. I would strongly advise the rider to take his frame into the nearest Cannondale dealer.

He may end up with a brand spankin’ new frame for an incredibly good deal, or even free if he’s lucky.Ben

Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn’s column appears here each Tuesday.